Image sensors are widely used in digital still cameras, cellular phones, and security cameras, as well as in medical, automobile, and other applications. The technology used to manufacture image sensors, and especially complementary metal-oxide-semiconductor (“CMOS”) image sensors, has continued to advance at great pace, and the demands of higher resolution and lower power consumption have encouraged further miniaturization and integration of image sensors.
Conventional CMOS image sensors use color filter arrays (CFAs) with abutting square filters having a set of primary colors such as red, green, and blue (RGB) arranged in what is commonly known as a Bayer pattern. In some embodiments additional visible or nonvisible filters can be included in the color filter array to increase the sensitivity of the image sensor and/or provide imaging capabilities outside the visible range of wavelengths.
But the additional pixels can reduce resolution and cause color aliasing. Resolution can be reduced if non-visible filters are used because they decrease the number of visible pixels. Color aliasing results in the wrong color appearing in an area of the image.